Pearl Izumi and Castelli have both been conducting wind tunnel tests since 2011 of race suits and arrived at a similar result: Tight, sleeveless tri suits are fast but can still be improved upon substantially. The counterargument is heat dissipation. Covering the arms and shoulders might increase core temp, especially in a hot and humid event such as Kona. Despite that concern, some top athletes raced the 2013 world championship in aero-specific race apparel.

Most still sported a traditional tri kit with short sleeves and the net benefit and lasting popularity of this new fashion is yet to be determined. But age groupers and pros alike may start adopting long-sleeve race apparel in big numbers next year on the back of these early adopters.

Luke McKenzie tore down the Queen K wearing an unbranded long-sleeve one-piece race kit. He elected to go with this suit after extensive testing at the L.A. Velodrome using the Alphamantis Track Aero System. The fast-wheeling Aussie and Canadian pro Heather Wurtele each raced in the same suit—only the zipper pull gave it away as a Champion System kit, the Apex Tri Speedsuit.

Full-sleeve triathlon kits are great for the bike leg, but shoulder coverage can be a problem when running in the heat. A removable top is Castelli’s solution for cutting drag while cycling without con- tributing to overheating during the run. Tim O’Donnell pulled the T1 Stealth Top over his tri kit after the swim and stripped it off for the run.

Craig Alexander also opted for a one-piece suit with long sleeves. His yet-to-be-named Louis Garneau race kit covers his armpits and shoulders to help smooth airflow around his back. Alexander prefers a thin chamois, so Garneau customised his Kona kit with a fleece pad instead of the thicker foam version that will come on the production version when it’s released later this year.